Microbiology: Microbial Nutrition and Growth PDF

Microbiology with Diseases by Body System Fifth Edition Chapter 6 Microbial Nutrition and Growth...

Microbiology with Diseases by Body System Fifth Edition Chapter 6 Microbial Nutrition and Growth PowerPoint® Lecture Presentations prepared by Mindy Miller-Kittrell, Wake Technical Community College Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (1 of 17) Microbial growth – Increase in a population of microbes – Due to reproduction of individual microbes Results of microbial growth – Discrete colony—an aggregation of cells arising from single parent cell – Biofilm—collection of microbes living on a surface in a complex community Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (2 of 17) Organisms use a variety of nutrients for their energy needs and to build organic molecules and cellular structures. Most common nutrients contain necessary elements such as carbon, oxygen, nitrogen, and hydrogen. Microbes obtain nutrients from variety of sources. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (3 of 17) Nutrients: Chemical and Energy Requirements – Sources of carbon, energy, and electrons ▪ Two groups of organisms based on source of carbon: – Autotrophs – Heterotrophs ▪ Two groups of organisms based on source of energy: – Chemotrophs – Phototrophs Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.1 Four Basic Groups of Organisms Based on Their Carbon and Energy Sources Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (4 of 17) Nutrients: Chemical and Energy Requirements – Sources of carbon, energy, and electrons ▪ Two groups of organisms based on source of electrons: – Organotrophs – Lithotrophs Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (5 of 17) Nutrients: Chemical and Energy Requirements – Oxygen requirements ▪ Oxygen is essential for obligate aerobes. ▪ Oxygen is deadly for obligate anaerobes. ▪ How can this be true? – Toxic forms of oxygen are highly reactive and excellent oxidizing agents. – Resulting oxidation causes irreparable damage to cells. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (6 of 17) Nutrients: Chemical and Energy Requirements – Oxygen requirements ▪ Four toxic forms of oxygen: – Singlet oxygen – Superoxide radicals – Peroxide anion – Hydroxyl radical Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (7 of 17) Nutrients: Chemical and Energy Requirements – Oxygen requirements ▪ Many organisms can live in various oxygen concentrations – Aerobes – Anaerobes – Facultative anaerobes – Aerotolerant anaerobes – Microaerophiles Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.2 Using a Liquid Thioglycolate Growth Medium to Identify the Oxygen Requirements of Organisms Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (8 of 17) Nutrients: Chemical and Energy Requirements – Nitrogen requirements ▪ Anabolism often ceases due to insufficient nitrogen. ▪ Nitrogen acquired from organic and inorganic nutrients ▪ All cells recycle nitrogen for amino acids and nucleotides. ▪ Nitrogen fixation by certain bacteria is essential to life on Earth. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (9 of 17) Nutrients: Chemical and Energy Requirements – Other chemical requirements ▪ Phosphorus ▪ Sulfur ▪ Trace elements – Only required in small amounts ▪ Growth factors – Necessary organic chemicals that cannot be synthesized by certain organisms Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Factor Function Amino acids Components of proteins Cholesterol Used by mycoplasmas (bacteria) for cell membranes Heme Functional portion of cytochromes in electron transport system NADH Electron carrier Niacin (nicotinic acid, vitamin B 3) Precursor of NAD+ and NADP+ Para-aminobenzoic acid (PABA) Precursor of folic acid, which is involved in metabolism of one- carbon compounds and nucleic acid synthesis Table 6.1 Some Growth Factors of Microorganisms and Their Functions Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (10 of 17) Physical Requirements – Temperature ▪ Temperature affects three-dimensional structure of proteins. ▪ Lipid-containing membranes of cells and organelles are temperature sensitive. – If too low, membranes become rigid and fragile. – If too high, membranes become too fluid. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.3 The Effects of Temperature on Microbial Growth Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.4 Five Categories of Microbes Based on Temperature Ranges for Growth Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.5 An Example of a Psychrophile Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (11 of 17) Physical Requirements – pH ▪ Organisms sensitive to changes in acidity – Hydrogen ions interfere with H bonding. ▪ Neutrophiles grow best in a narrow range around neutral pH. ▪ Acidophiles grow best in acidic habitats. ▪ Alkalinophiles live in alkaline soils and water. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (12 of 17) Physical Requirements – Physical effects of water ▪ Microbes require water to dissolve enzymes and nutrients. ▪ Water is important reactant in many metabolic reactions ▪ Most cells die in absence of water. – Some have cell walls that retain water. – Endospores and cysts cease most metabolic activity. ▪ Two physical effects of water: – Osmotic pressure – Hydrostatic pressure Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (13 of 17) Physical Requirements – Physical effects of water ▪ Osmotic pressure – Pressure exerted on a semipermeable membrane by a solution containing solutes that cannot freely cross the membrane – Hypotonic: solutions have lower solute concentrations. Cell placed in hypotonic solution swells. – Hypertonic: solutions have greater solute concentrations. Cell placed in hypertonic solution shrivels. – Restricts organisms to certain environments Obligate and facultative halophiles Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 3.20 Effects of isotonic, hypertonic, and hypotonic solutions on cells. Cells without a wall (e.g., mycoplasmas, H2 O H2 O animal cells) H2 O Cell wall Cell wall Cells with a wall H2 O H2 O H2 O (e.g., plants, fungal and bacterial cells) Cell membrane Cell membrane Isotonic Hypertonic Hypotonic solution solution solution Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (14 of 17) Physical Requirements – Physical effects of water ▪ Hydrostatic pressure – Water exerts pressure in proportion to its depth. – Barophiles live under extreme pressure. Their membranes and enzymes depend on pressure to maintain their three-dimensional, functional shape. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (15 of 17) Associations and Biofilms – Organisms live in association with different species: ▪ Antagonistic relationships ▪ Synergistic relationships ▪ Symbiotic relationships Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (16 of 17) Associations and Biofilms – Biofilms ▪ Complex relationships among numerous microorganisms ▪ Form on surfaces, medical devices, mucous membranes of digestive system – Form as a result of quorum sensing ▪ Many microorganisms are more harmful as part of a biofilm ▪ Scientists seeking ways to prevent biofilm formation Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.6 Biofilm Development Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.7 Quorum Sensing Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth Requirements (17 of 17) Tell Me Why – Why should cardiac nurses and respiratory therapists care about biofilms? Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (1 of 12) Culture – Act of cultivating microorganisms or the microorganisms that are cultivated Inoculum of microorganisms introduced into medium containing nutrients Inocula obtained from various sources – Environmental specimens – Clinical specimens – Stored specimens Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.8 Characteristics of Bacterial Colonies Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Table 6.2 Clinical Specimens and the Methods Used to Collect Them Type or Location of Specimen Collection Method Skin, accessible membrane (including eye, Sterile swab brushed across the surface; care should be outer ear, nose, throat, vagina, cervix, taken not to contact neighboring tissues urethra), or open wounds Blood Needle aspiration from vein; anticoagulants are included in the specimen transfer tube Cerebrospinal fluid Needle aspiration from subarachnoid space of spinal column Stomach Intubation, which involves inserting a tube into the stomach, often via a nostril Urine In aseptic collection, a catheter is inserted into the bladder through the urethra; in the “clean catch” method, initial urination washes the urethra, and the specimen is midstream urine Lungs Collection of sputum either dislodged by coughing or acquired via a catheter Diseased tissue Surgical removal (biopsy) Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (2 of 12) Obtaining Pure Cultures – Cultures composed of cells arising from a single progenitor ▪ Progenitor is termed a colony-forming unit (CFU). – Aseptic technique prevents contamination of sterile substances or objects. – Two common isolation techniques: ▪ Streak plates ▪ Pour plates Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.9 The Streak-Plate Method of Isolation Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.10 The Pour-Plate Method of Isolation Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (3 of 12) Obtaining Pure Cultures – Other isolation techniques ▪ Some fungi isolated with streak and pour plates. ▪ Protozoa and motile unicellular algae isolated through dilution of broth cultures ▪ Can individually pick single cell of some large microorganisms and use to establish a culture Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (4 of 12) Culture Media – Majority of prokaryotes have not been grown in culture medium – Variety of liquid and solid media used to culture microbes ▪ Nutrient broth is a common liquid medium. ▪ Agar is a common addition to make media solid. – Used to make Petri plates and slant tubes Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.11 Slant Tubes Containing Solid Media Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (5 of 12) Culture Media – Six types of general culture media: ▪ Defined media ▪ Complex media ▪ Selective media ▪ Differential media ▪ Anaerobic media ▪ Transport media Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved  Ingredient Amount Glucose 1.0 g Na2HPO4 16.4 g KH2PO4 1.5 g (NH4)3PO4 2.0 g MgSO M gSO4  7H 2O 7 H 2 O 4 dot 0.2 g CaCl2 0.01 g FFeSO eSO 4 4 7Hdot 2O 7 H 2 O 0.005 g Distilled or deionized water Enough to bring volume to 1 L Table 6.3 Ingredients of a Representative Defined (Synthetic) Medium for Culturing E. coli Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (6 of 12) Culture Media – Complex media ▪ Exact chemical composition is unknown ▪ Nutrients commonly derived from breakdown of yeast, beef, soy, and proteins ▪ Supports growth of a wide variety of microorganisms ▪ Useful when nutritional needs of an organism are unknown – Selective media ▪ Contain substances that favor or inhibit growth of particular microorganisms Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.12 An Example of the Use of a Selective Medium Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (7 of 12) Culture Media – Selective media ▪ Enrichment culture – Selective medium used to increase small numbers of a microbe to observable levels ▪ Cold enrichment – Enrich a culture with cold-tolerant species. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.13 The Use of Blood Agar as a Differential Medium Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (8 of 12) Culture Media – Differential media ▪ Different bacteria growing on the media distinguished by – Presence of visible changes in the medium – Differences in the appearance of colonies Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.14 The Use of Carbohydrate Utilization Tubes as Differential Media Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Table 6.4 Representative Differential Complex Media MacConkey Medium Medium and Ingredients Use and Interpretation of Results Peptone (20.0 g) For the culture and differentiation of enteric bacteria based on Agar (12.0 g) the ability to ferment lactose Lactose (10.0 g) Lactose-fermenters produce red-to-pink colonies; non-lactose- fermenters form colorless or transparent colonies Bile salts (5.0 g) NaCl (5.0 g) Neutral red (0.075 g) Crystal violet (0.001 g) Water to bring volume to 1 L Blood Agar Medium and Ingredients Use and Interpretation of Results Agar (15.0 g) For culture of fastidious microorganisms and differentiation of Pancreatic digest of casein (15.0 g) hemolytic microorganisms Papaic digest of soybean meal (5.0 g) Partial digestion of blood: alpha-hemolysis; complete digestion of blood: beta-hemolysis; no digestion of blood: gamma-hemolysis NaCl (5.0 g) Water to bring volume to 950.0 ml Sterile blood (50.0 ml, added to medium after autoclaving and cooling) Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.15 The Use of Macconkey Agar as a Selective and Differential Medium Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.16 An Anaerobic Culture System Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (9 of 12) Culture Media – Transport media ▪ Used by health care personnel to ensure clinical specimens are not contaminated and to protect people from infection ▪ Rapid transport of samples is important. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (10 of 12) Special Culture Techniques – Techniques developed for culturing microorganisms ▪ Animal and cell culture – Used when artificial media is inadequate – Viruses only grow within living cells. ▪ Low-oxygen culture – Carbon dioxide incubators mimic the environment of certain body tissues. – Candle jars create environment with low oxygen and high CO2 levels. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (11 of 12) Preserving Cultures – Refrigeration ▪ Stores for short periods of time – Deep-freezing ▪ Stores for years – Lyophilization ▪ Stores for decades Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Culturing Microorganisms (12 of 12) Tell Me Why – Why do clinical laboratory scientists keep many different kinds of culture media on hand? Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (1 of 9) Most microorganisms reproduce by binary fission. – One divides in half to produce two daughter cells. – Involves four steps Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Bacterial Growth: Overview Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.17 Binary Fission Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Binary Fission Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (2 of 9) Generation Time – Time required for a bacterial cell to grow and divide – Dependent on chemical and physical conditions Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.19 Two Growth Curves of Logarithmic Growth Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.20 A Typical Population Growth Curve Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Bacterial Growth Curve Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (3 of 9) Continuous Culture in a Chemostat – Chemostat used to maintain a microbial population in a particular phase of growth – Open system ▪ Requires addition of fresh medium and removal of old medium – Used in several industrial settings Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.21 Schematic of Chemostat Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (4 of 9) Measuring Microbial Reproduction – Estimating the number of microorganisms is useful ▪ Determine severity of certain infections ▪ Determine effectiveness of food preservation techniques ▪ Measure the degree of contamination of water supplies ▪ Evaluate disinfectants and antibiotics – Direct methods not requiring incubation ▪ Microscopic counts Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.22 The Use of a Cell Counter for Estimating Microbial Numbers Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (5 of 9) Measuring Microbial Reproduction – Direct methods not requiring incubation ▪ Electronic counters – Coulter counter Counts cells as they interrupt an electrical current – Flow cytometry Detects changes in light transmission as cells pass a detector Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (6 of 9) Measuring Microbial Reproduction – Direct methods requiring incubation ▪ Serial dilution and viable plate counts ▪ Membrane filtration ▪ Most probable number Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.23 A Serial Dilution and Viable Plate Count for Estimating Microbial Population Size Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.24 The Use of Membrane Filtration to Estimate Microbial Population Size Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.25 The Most Probable Number (M P N) Method for Estimating Microbial Numbers Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Table 6.5 Most Probable Number Table (Partial) (1 of 2) Number Out of Five Number Out of Number Out of Tubes Giving Positive Five Tubes Most Probable Five Tubes Giving Results in Thr ee Dilutions Giving Positive Number of Positive Results in Results in Three Bacteria per 100 Dilutions Three Dilutions ml 4 0 0 13 4 0 1 17 4 1 0 17 4 1 1 21 4 1 2 26 4 2 0 22 4 2 1 26 4 3 0 27 4 3 1 33 4 4 0 34 5 0 0 23 5 0 1 30 5 0 2 40 5 1 0 30 5 1 1 50 Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Table 6.5 Most Probable Number Table (Partial) (2 of 2) Number Out of Five Number Out of Number Out of Tubes Giving Positive Five Tubes Most Probable Five Tubes Giving Results in Thr ee Giving Positive Number of Dilutions Positive Results in Results in Three Bacteria per 100 Dilutions Three Dilutions ml 5 1 2 60 5 2 0 50 5 2 1 70 5 2 2 90 5 3 0 80 5 3 1 110 5 3 2 140 5 3 3 170 5 4 0 130 5 4 1 170 5 4 2 220 5 4 3 280 5 4 4 350 Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (7 of 9) Measuring Microbial Growth – Indirect methods ▪ Turbidity – Often the more turbid a culture, the greater the bacterial population Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Figure 6.26 Turbidity and the Use of Spectrophotometry in Indirect Measurement of Population Size Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (8 of 9) Measuring Microbial Growth – Indirect methods ▪ Metabolic activity ▪ Dry weight ▪ Molecular methods – Isolate DNA sequences of unculturable prokaryotes Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Growth of Microbial Populations (9 of 9) Tell Me Why – Some students transfer some “gunk” from a 2-week- old bacterial culture into new media. Why shouldn’t they be surprised when this “death-phase” sample grows? Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved Micro Matters In the Micro Matters video in Chapter 6, Jen and Mike learn about the cause of listeriosis, Listeria monocytogenes. – Listeria monocytogenes survives in a variety of environmental conditions. – Listeria monocytogenes can cause central nervous system (CNS) infections in individuals with a weakened immune system. – Listeria monocytogenes can be identified using selective and differential media. – Some antibiotics used to treat listeriosis are inhibitors of bacterial enzymes. Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved  Week 3 Quiz Note that you must use the Respondus Lockdown Browser for the Week 3 in-class quiz. Bring your laptops in the class, make sure you downloaded Respondus and it is working before attending. Week 3 Quiz 1: 90 points (It will cover Chapters 1, 3, 5, and 6). Copyright © 2021, 2018, 2015 Pearson Education, Inc. All Rights Reserved